A good kind of D

Research is showing that vitamin D plays an ever-important role in our health. Here’s the latest on how that relates to kids (who apparently aren’t getting as much D as they need):

Low Vitamin D Levels Put Healthy Children at Risk

By Joi Preciphs

Bloomberg News

More than half of healthy children in a study in the U.S. Northeast had low blood levels of vitamin D, especially in winter, putting them at risk for weakened bones and diseases including cancer.

Of the 382 children examined from northeastern states, 55 percent had low levels overall, rising to 68 percent during winter months, according to a study appearing in the American Journal of Clinical Nutrition. More than 90 percent of black children had low blood levels of vitamin D, and about a fifth had readings associated with rickets and other diseases of the bones or muscles.

The findings in healthy children call dietary recommendations into question, the researchers said. Vitamin D deficiency can lead to poor absorption of bone minerals and may contribute to cancer, multiple sclerosis, hypertension and diabetes, the researchers said. Children over age 9, those who didn’t get enough of the vitamin in food or supplements, and black children were most at risk.

“Many children with chronic diseases have suboptimal vitamin D status,” said Babette Zemel, the director of the Nutrition and Growth Laboratory at the Children’s Hospital of Philadelphia. “The study provides evidence that this is cause for concern in otherwise healthy children.”

Zemel and colleagues at the University of Pennsylvania School of Medicine measured a biomarker for vitamin D in the blood of children from 6 to 21 years of age. The researchers also assessed the intake of vitamin D from food and supplements and measured the children’s body mass. Fortified milk is the primary source of the vitamin in the diet, the scientists said.

Children with vitamin D deficiencies tended to live in households with low incomes, have undereducated caregivers and carry excess weight, the researchers found. Optimal vitamin D levels were established in previous studies, and exposure to sunshine is the best way to boost levels in the blood, the researchers said. Although sunlight exposure wasn’t measured in the study, the explanation for lower vitamin D in older children is probably related to decreased outdoor activity, the researchers said.

“Vitamin D deficiency remains an under-recognized problem overall, and is not well studied in children,” Zemel said in a statement accompanying the article. Further research should measure sun exposure and be conducted at multiple sites, the researchers said.

Vitamin D-deficient diets are also associated with milk allergy; intolerance to lactose, a sugar found in dairy products; and strict vegetarianism. More than 80 percent of blacks, American Indians and Asian Americans are lactose intolerant.

The research was supported by grants from the U.S. National Institutes of Health; the Nichols Institute, a subsidiary of Quest Diagnostics Inc., and its medical director, Richard Reitz; and two separate research institutes of the Children’s Hospital of Philadelphia. The journal is published by the American Society for Nutrition, based in Bethesda, Maryland.